The Sunday morning air hung heavy with humidity, leaving skin covered in a sticky film, and a gray pall covered the sky, threatening rain that would later fall. Observers — of all ages — settled into their spots, a buzzed excitement as clocks ticked ever so closer to 8 a.m. To the average Ames resident’s eye, it felt like a normal, less-than-sunny day. But for the triathletes lined up at the lake shore of Ada Hayden Heritage Park, it was the day to put their training to the test.